<?php 
/**
 *  encrypt
 */
namespace Client\Common;

class EncryptHelper
{   
    public $length = 8;
    public $password;
    public function createSalt(){
        // 密码字符集，可任意添加你需要的字符
        $chars = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
    
        $salt = '';
        for ( $i = 0; $i < $this->length; $i++ ) 
        {
            // 这里提供两种字符获取方式
            // 第一种是使用 substr 截取$chars中的任意一位字符；
            // 第二种是取字符数组 $chars 的任意元素
            // $password .= substr($chars, mt_rand(0, strlen($chars) - 1), 1);
            $salt .= $chars[ mt_rand(0, strlen($chars) - 1) ];
        }
        return $salt;  
    }
    
    public function encryptPwd(){   
        return md5(sha1(trim($this->password)));
    }
   

    public function authcode($string, $operation = 'DECODE', $key = '', $expiry = 0){
        $ckey_length = 4;
//        $key = md5($key != '' ? $key : getglobal('authkey'));
        $keya = md5(substr($key, 0, 16));
        $keyb = md5(substr($key, 16, 16));
        $keyc = $ckey_length ? ($operation == 'DECODE' ? substr($string, 0, $ckey_length): substr(md5(microtime()), -$ckey_length)) : '';
    
        $cryptkey = $keya.md5($keya.$keyc);
        $key_length = strlen($cryptkey);
    
        $string = $operation == 'DECODE' ? base64_decode(substr($string, $ckey_length)) : sprintf('%010d', $expiry ? $expiry + time() : 0).substr(md5($string.$keyb), 0, 16).$string;
        $string_length = strlen($string);
    
        $result = '';
        $box = range(0, 255);
    
        $rndkey = array();
        for($i = 0; $i <= 255; $i++) {
            $rndkey[$i] = ord($cryptkey[$i % $key_length]);
        }
    
        for($j = $i = 0; $i < 256; $i++) {
            $j = ($j + $box[$i] + $rndkey[$i]) % 256;
            $tmp = $box[$i];
            $box[$i] = $box[$j];
            $box[$j] = $tmp;
        }
    
        for($a = $j = $i = 0; $i < $string_length; $i++) {
            $a = ($a + 1) % 256;
            $j = ($j + $box[$a]) % 256;
            $tmp = $box[$a];
            $box[$a] = $box[$j];
            $box[$j] = $tmp;
            $result .= chr(ord($string[$i]) ^ ($box[($box[$a] + $box[$j]) % 256]));
        }
    
        if($operation == 'DECODE') {
            if((substr($result, 0, 10) == 0 || substr($result, 0, 10) - time() > 0) && substr($result, 10, 16) == substr(md5(substr($result, 26).$keyb), 0, 16)) {
                return substr($result, 26);
            } else {
                return '';
            }
        } else {
            return $keyc.str_replace('=', '', base64_encode($result));
        }
    
    }
    
    /**
     * 异位或加密字符串
     * @param  [String]  $value [需要加密的字符串]
     * @param  [integer] $type  [加密解密（0：加密，1：解密）]
     * @return [String]         [加密或解密后的字符串]
     */
    function encryption($value, $type=0){
        $encoding_aes_key = 'zswjycfx';
        $encryptionKey = md5($encoding_aes_key);
        if(!$type){
            return str_replace('=', '', base64_encode($value ^ $encryptionKey));
        }
        $value = base64_decode($value);
        return $value ^ $encryptionKey;
    }
    
}